In all flat panel displays such as liquid crystal displays (LCD) and organic light emitting diode (OLED) displays, a plurality of arrayed pixels are included. Each pixel generally includes sub-pixels in red, green and blue, each of the sub-pixels controlled by a gate line and a data line. The gate line is used to control ON and OFF of the sub-pixels, while the data line applies different data voltage signals to the sub-pixels, such that the sub-pixels are displayed in different gray scales so as to realize full-color screen display.